LOS ANGELES — A German man who spread fear across Los Angeles for several nights as he torched cars and homes to avenge his mother’s deportation was convicted Thursday of nearly 50 arson counts.

Harry Burkhart, 29, objected to the verdict, which carries a potential prison sentence of nearly 90 years.

“There were a lot of unfair claims I wish I could do something about,” he told the judge through a German interpreter. The judge said Burkhart could take that up on appeal.

Jurors were told to return to court next week to begin determining whether the ex-Frankfurt resident was sane at the time of the crimes. If not, he could be sent to a mental institution.

Burkhart had threatened to “roast America” after his mother, Dorothee Burkhart, was ordered extradited to Germany to face fraud charges, prosecutors said.

Burkhart placed incendiary devices under cars in Hollywood, the San Fernando Valley and West Hollywood on Dec. 30 and Dec. 31, 2011, and on Jan. 2, 2012, authorities said. Some vehicles were in carports and in 19 cases the fires spread to homes and apartments.

The sheer number of fires “brought the fire department in this city to its knees,” Los Angeles County prosecutor Sean Carney told jurors in his opening statement.

Defense attorney Steve Schoenfield told jurors that the prosecution had linked his client to only six or seven fires and “copycats” might have started others.

There were no serious injuries or deaths as a result of the fires but damages were estimated to be more than $3 million.

Burkhart “wanted America to burn” and “was going to resolve his grievance through fire and fear,” Carney said. “He was ready to set many more.”

Burkhart was arrested in 2012. Burkhart’s anti-American outburst during a detention hearing for his mother in 2011 cemented his likeness in the mind of a deputy U.S. marshal, who authorities say recognized him after police began circulating a video showing the man wanted in the arson spree.