Steven Seagal -- Legal Threats Over Tank Raid

The blood of a dead puppy is on Steven Seagal's hands ... this according to an Arizona man who claims the actor participated in a deadly police raid on his home back in March that was taped for a reality show.

Seagal, along with Maricopa County Sheriff Joe Arpaio, has been served with an official notice of claim from Jesus Sanchez Llovera -- who contends Seagal and the Maricopa County Sheriff's Department performed an "unfounded" raid on his home because they believed Jesus was operating an illegal cockfighting farm. Jesus denies the allegation -- insisting he only raises the roosters "for show."

Jesus claims Seagal arrived to his home on March 9 with a TANK -- and rammed into a gate on his property. Seagal was backed up by an MCSO Tactical Operations Unit -- armed in full riot gear -- which stormed the house. The entire incident was captured by a camera crew taping for Seagal's reality show, "Steven Seagal Lawman."

Jesus claims his 11-month old puppy was shot and killed during the raid -- and his home sustained "substantial damage." He also claims the cops killed more than 100 roosters that belonged to him.

The notice of claim is the first step towards a lawsuit -- and Jesus' lawyer tells us his client is demanding $100,000 for the damage and he wants Seagal to issue a "formal written apology" to his children "for the death of their 11-month old puppy, a beloved family pet."