L.A. arson suspect Harry Burkhart -- who was arrested Monday in connection with over 50 fires set in the Hollywood area since last week -- has been placed on suicide watch ... this according to the L.A. Times.

It's unclear what Burkhart said during the interrogation process that resulted in the suicide watch.

According to the report ... Burkhart has refused to cooperate with authorities in the interrogation -- saying nothing whatsoever about the fires.

When he did speak, sources tell the Times, Burkhart went on anti-American rants, blasting law enforcement.


2:17 PM PT: Harry has just been charged with 37 felony counts of arson -- 28 counts of arson of property and 9 counts of arson of an inhabited structure. He's scheduled to be arraigned this afternoon.

According to the D.A., Burkhart used a device "designed to accelerate the fire" -- a serious allegation that, if true, would mean even more prison time for Burkhart.

A TMZ producer was in the parking garage where the prime arson suspect was captured on surveillance video Friday ... and just an hour before a car in the garage was ignited, the producer saw ANOTHER man casing the vehicle.

Three law enforcement agencies have contacted our producer multiple times since the incident, asking him numerous questions about what he observed.

The producer was going to the gym in the building at around 6 PM on Friday.  As he tried to find a parking space ... he saw a gray, 1990s Monte Carlo blocking a car that was about to be torched.  There were 2 people in the Monte Carlo -- a driver and another man who was tampering with the vehicle that would soon explode in flames.  Our producer says both men appeared to be in their 20s.  He could not ID the driver, but says the man tampering with the car had long-ish black hair, which was NOT in a ponytail.

The producer went to the gym, and an hour later ... as he drove past the targeted car, it exploded in flames.

Our producer called LAPD and told them what he saw.  He then received numerous calls from detectives and fire chiefs.  Authorities described the man who would become the prime suspect Harry Burkhart -- the man with the ponytail -- but our producer said that was NOT the man he saw tampering with the car.

LA City Fire Department Captain Jamie Moore tells TMZ ... the investigation is still active and they are not ruling out accomplices.

LASD officers swarmed and handcuffed what they described as a "person of interest" in the Los Angeles arsonist spree that has left thousands of residents scared out of their wits for days.

Fire officials say "it is too early to speculate" if this is the person responsible for the fires.

Police have already released surveillance video showing the alleged suspect -- a ponytailed Steven Seagal lookalike (below). As you can see in our video ... the man in custody sports a ponytail



Cops previously said 39 fires could be linked to the recent rash of arsons ... and another 11 were reportedly set last night.

It's not 100% clear from the footage -- but several witnesses confirm what appears to be a creepy smile on the man's face as he sat in the back of the squad car (below).



6:19 PM PT: The man has been identified as 24-year-old Harry Burkhart, a Hollywood resident. During a news conference moments ago, Mayor Villaraigosa said Burkhart is currently being held without bail.

According to Villaraigosa, the arson fires that ravaged Hollywood the last 4 days -- over 50 in total -- have caused over $3 million in damage.

L.A. County Sheriff Lee Baca said, "The serial arsonist, I believe, has been caught" -- but LAPD Chief Charlie Beck pointed out ... it's still unclear if the arson fires were a one-man operation.

12:10 PM PT: Police say the man has been arrested and is currently being booked.

9:32 AM PT: Riding in an equestrian unit this morning at the Rose Parade, LAPD Chief Charlie Beck said, "We are we are very confident we found our man."

8:13 AM PT: Police say fire-starting materials were found in the man's van, which displayed Canadian license plates. According to reports, the materials include charcoal.


8:00 AM PT: There are reports the man may be a German national, who is angry that his mother is being deported from the US. An immigration agent helped identify him.