TAIPEI (Taiwan News) — National Police Agency (NPA) Director-General Chen Chia-chin (陳家欽) vowed to appeal against the not guilty verdict handed down Thursday (April 30) by the Chiayi District Court in a cop slaying case on grounds that the defendant was suffering from mental illness.

Chen said that the nation's entire police force could not accept the sentence, which was tantamount to saying killing a police officer was not a crime, CNA reported.

The defendant surnamed Cheng (鄭), 54, stabbed railway police officer Lee Cheng-han (李承翰), 24, to death on July 3 last year during an altercation stemming from a ticket issue. The court acquitted the defendant explaining that he was suffering from schizophrenia and had not been taking medications regularly, according to the report. Cheng would be ordered to live at a certain location and monitored for five years after posting NT$500,000 (US$16,700) bail.

The NPA issued a statement, saying that the sentence was extremely unfair and totally unacceptable. Killers of law enforcement officers should be strongly condemned and prosecuted or the safety of police and their morale would be seriously compromised, the statement said.

The NPA urged prosecutors to appeal against the sentence and said it would hire lawyers to help the victim’s family with the appeal.